Applying pdf watermark at typescript side

Question

I am trying to add a watermark to pdf and image files that I show at the frontend where I use angular with typescript.

I could not find a module that I could use for pdf. I found that on node side there is a library that I tried to use using image-watermark "const watermark = require('image-watermark');" but it seems that require does give me an error when I run ng serve -o. I used the follwoing github source https://github.com/luthraG/image-watermark